U groove traction elevator



y B. A. SCHROEDER 1,865,911

U GROOVE TRACTION ELEVATOR Filed April '7, 1928 Patented July 12, 1932PATENT OFFICE BERNARD A. SCI'IROEDER, OF WILME'TTE, ILLINOIS U GROOVETRACTION ELEVATOR Application filed April 7,

This invention relates particularly to traction elevators of theU-groove type and, more particularly, to an improved hoisting drumhaving a spiral shaped groove and a means for compensating thelongitudinal travel of the cables on such a drum during its operation.

The earlier elevator machines were generally of the winding drum type.The car hoisting cables and the counterweight cables were attacheddirectly to the drum so as to permit one set to wind up on the drum asthe other unwound. In recent years, however, traction-ty e elevatormachines have found so much avor that manufacture of the former has beenpractically discontinued.

Traction elevators are divided into two types, known as V-groove andU-groove, deriving their names from the contour of ,1 the groove on theperiphery of the drum or traction sheave.

Traction elevators have continuous lengths of cable extending from theelevator car, around the drum, and down to the counterweight. V-groovedrums exert a slight Wedging action on the cable and one-half a turn ofcontact surface with the drum has been found sufficient for small lifts.In higher installations Where the car speed is increased and the wedgingaction is greater, due to the additional weight of the cables, U-groovemachines have been found more satisfactory.

With a U-groove installation, more contact surface is required to givenecessary traction between the drum and the cables.

The usual practice has been to provide more surface by installing anidler sheave below the drum and passing the cable up from the car, overthe drum, down under the idler sheave, up over the drum again and downto the counterweight. The idler may also act as a deflecting sheave ifthe width of the shaftway requires one. By the use of an idler sheave,an additional half turn of tractive surface was obtained Without havingany longitudinal travel of the cables on the drum.

It is a specific object of this invention to avoid the use of an idlersheave by providing a drum with a spiral shaped groove 1928. Serial No.268,113.

and to compensate for the longitudinal travel of cables on the drum bymoving the drum in the opposite direction to such travel. Thiscompensating movement may be accomplished by means of a screw-shaftseparate from machine bearings and carrying none of the weight of thecar, counterweight, cables or machine.

Further and more specific objects of the invention will become apparentas the specification proceeds and by references to the accompanyingdrawing, in which Figure 1 is an elevational view of an embodiment ofthe invention; Fig. 2, an elevational view of another embodiment of theinvention; Fi 3, a vertical sectional view taken as indicated at line3-3 of Fig. 1; Fig. 1, a diagrammatic view of the proposed installation;and Fig. 5, a diagrammatic view of the present type of installation.

Referring now to the drawing, Figure 1 illustrates a portion of theequipment of the ordinary gearless traction elevator in which thesupporting frame is generally designated by the numeral 10 and thestandards by the numeral 11. A shaft 12 is suitably mounted in bearings13 and carries a drum 14 about which the cables 15 are wrappedsubstantially one and one half turns.

The shaft 12 and drum 1 1 are actuated by a motor 16 to which the shaftis connected at one end by means of an expansion and contractionmechanism generally designated by the numeral 17. The other end of theshaft 12 projects beyond the adjacent supporting bearing 13. An arm 18provides at its upper end portion a bearing 19 for the projecting end ofthe shaft 12, both the shaft and the bearing being threaded wherebyrotation of the shaft imparts a longitudinal motion to the shaftrelative to the bearings 13 and 19 in which it rotates. The arm 18 andthe bearing 19 do not carry any of the weight or load from the drum M-or the shaft 12 but are provided merely to impart longitudinal movementto the shaft and the drum. By not carrying any of the load to thebearing 19, longitudinal movement of the shaft is accomplished with onlya small part of the frictional resistance present where the bearingshaft is threaded.

The expansion and contraction mechanism 17 permits the longitudinalmovement of the shaft 12 back and forth as the direction of travelalternates and also transmits the necessary torsional force to rotatethe shaft and the drum 14. The mechanism 17 comprises two groups of fourlevers each, respectively designated as 20 and 21. The levers 20 arefastened at one end to the motor shaft 22 by means of wrist pins 23 andthe levers 21 are similarly fastened to the shaft 12 by pins 23. Thelevers 21 are forked at their outer ends to receive the correspondingend of lever 20. The outer ends of each of the levers 21 are fastened tothe outer end of a corresponding lever 20 by a pin 24 thereby making acomplete coupling of the shafts 12 and 22.

The drum 14 has a spiral groove 25 formed in its outer periphery inwhich are shown six separate cables 15, each wrapped substantially oneand one half turns about the drum. One end of the cables 15 leadsdownward through an opening 27 in the frame 10 to the top of theelevator car 28, shown diagrammatically in Fig. 4. The other end of thecable 15 leads to the deflecting sheave 29 and down to the counterweight 30 also shown diagrammatically in Fig. 4. In the position shownin Fig. 1, the elevator car 28 has reached its topmost position and thedrum 14 and the shaft 12 have reached their extreme position of movementto the left caused by the rotation of the shaft 12 in its threadedbearing 19. The pitch of the screw 31 in the end of the shaft 12 is madethe same as the pitch of the spiral groove 25 so that the cables 15remain continuously in the same vertical plane and the travel of thecables in the groove 25 is thus compensated for.

As the motor 16 actuates the mechanism 17 to rotate the shaft 12 and thedrum 14 in anti-clockwise direction, viewed from the right end of theshaft, the elevator is raised and the shaft and drum travel to the rightan amount equivalent to the pitch of the groove 25 and the screw 31.Continued rotation in the same direction will cause the cables 15 totravel to their extreme left position in the groove 25 and the shaft 12and the drum 14 to move the maximum amount to the right and themechanism 17 to move to its position of maximum contraction as shown indotted lines.

In Figure 2 is shown another embodiment of the invention in which themotor 16 and drum 14 are mounted adjacent to each other on the shaft 12.The shaft 12 is supported by the standards 35 and 36 carried by theframe or base 37. A sub-base 38 provides a support or track on which thebase 37 travels on rollers 49 positioned between the base 37 and thesub-base 38. Longitudinal channels 50 formed in. the bottom of the base37, provide races or runways for the roller bearings 49. The threadedbearing 39 loosely fits and provides a control for the longitudinalmovement of the shaft 12. The roller bearings 49 provide for themovement of the base 37 with the shaft 12, the weight of all of theelements supported on or suspended from the base, being carried by therollers with a minimum of frictional resistance.

The outer end of the shaft 12 projects beyond the standard 35 and isthreaded to engage a similarly threaded bearing 39 in the top of astandard 40. The standard 40 is mounted upon the sub-base 38. The otherend of the shaft is mounted in the standard 36 in a thrust bearing 41. Abrake 42 is positioned between the standard 36 and the drum 14. The drum14 is provided with a spiral groove 25 of the same pitch as the screw 43in the end of the shaft 12 and in which six cables 15 are wrapped forsubstantially one and one half turns as in the embodiment of Fig. 1. Thecables 15 extend downwardly through an opening 44 in the base 37 and acorresponding opening 51 in the sub-base 38. Upon actuation of the drum14 by the motor 16, as described in the embodiment shown in Fig. 1, thesame compensation for the travel of the cables 15 in the groove 25occurs by reason of the travel of the entire base 37 carrying with itthe motor and drum whereby each of the cables remain in their respectivevertical planes. The bearing 39 and the shaft 12 are so constructed andarranged that no weight is carried by the hearing, all of the weight ofthe moving parts as well as the weight of the car 28, the cable 15 andcounterweights 30 being carried by the frame or base 37.

Obviously, certain changes may be made and different combinations madeof the parts without departing from the spirit of the invention.

The foregoing detailed description is given for clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom, but the appended claims should be construed as broadly aspermissible, in view of the prior art.

I claim:

1. In apparatus of the kind described, a base member, a sub-base member,a driven shaft, bearing supports in which said shaft is rotatablymounted, said bearing supports being fixedly mounted on the base member,

means preventing longitudinal movement of the shaft in its bearingsupports, and a bearing fixedly mounted on the sub-base member, saidbearing loosely fitting and having a threaded connection with the shaft,and said base member being supported upon and movable relative to thesub-base member.

2. In apparatus of the kind described, a base member, a sub-base member,a driven shaft, bearing supports in which saidshaft 1' is rotatablymounted, said bearing supports being fixedly mounted on the base member,means preventing longitudinal movement of the shaft in its bearingsupports, a bearing fixedly mounted on the sub-base member, said bearingloosely fitting and having a threaded connection with the shaft, saidbase member being supported upon and movable relative to the sub-basemember and roller bearings positioned between the lower face of the basemember and the upper face of the sub-base member.

3. In apparatus of the kind described, a sub-base member, a base membermounted upon and movable relative to the sub-base member, a drivenshaft, a cable drum fixedly mounted on the shaft, bearing supports uponwhich the shaft is rotatably mounted, said bearing supports beingfixedly mounted on the base member, means preventing longitudinalmovement of the shaft in said supports, and a bearing fixedly mounted onthe subbase member, said bearing loosely fitting and having threadedconnection with the shaft, whereby rotation of the shaft operates tomove the base member, shaft and drum, longitudinally of the shaft.

4. In apparatus of the kind described, a sub-base member, a base membermounted upon and movable relative to the sub-base member, a drivenshaft, a cable drum fixedly mounted on the shaft, bearing supports uponwhich the shaft is rotatably mounted, said bearing supports beingfixedly mounted on the base member, means preventing longitudinalmovement of the shaft in said sup ports, a bearing fixedly mounted onthe subbase member, said bearing loosely fitting and having a threadedconnection with the shaft and roller bearings positioned between thelower face of the base member and the upper face of the sub-base member.

5. In apparatus of the kind described, a sub-base member, a base membermounted upon and movable relative to the sub-base member, a drivenshaft, a cable drum fixedly mounted on the shaft, bearing supports uponwhich the shaft is rotatably mounted, said bearing supports beingfixedly mounted on the base member, means preventing longitudinalmovement of the shaft in said supports, a bearing fixedly mounted on thesubbase member, said bearing loosely fitting and having a threadedconnection with the shaft operable to move the base member, shaft anddrum longitudinally of the shaft when the shaft is rotated and drivingmechanism fixedly mounted upon the base member operable to rotate theshaft.

6. In apparatus of the kind described, a sub-base member, a base membermounted upon and movable relative to the sub-base member, a drivenshaft, a cable drum fixedly mounted on the shaft, said drum having ahelical groove in its outer periphery, bearing supports upon which theshaft is rotatably mounted, said bearing supports being fixedly mountedon the base member, means preventinglongitudinal movement of the shaftin said supports, a bearing fixedly mounted on the sub-base member, saidbearing loosely fitting and having a threaded connection with the shaft,and roller bearings positioned between the lower face of the base memberand the upper face of the sub-base member.

7. In apparatus of the kind described, a sub-base member, a base membermounted upon and movable relative to the sub-base member, a drivenshaft, a cable drum fixedly mounted on the shaft, said drum having ahelical groove in its outer periphery, bearing supports upon which theshaft is rotatably mounted, said bearing supports being fixedly mountedon the base member, means preventing longitudinal movement of the shaftin said supports, a bearing fixedly mounted on the sub-base member, saidbearing loosely fitting and having a threaded connection with the shaft,the pitch of the shaft and fixed bearing being the same as that of thehelical groove, and roller bearings positioned between the lower face ofthe base member and the upper face of the sub-base member.

8. In apparatus of the character set forth, a shaft, a cable drumfixedly mounted on said shaft, bearing supports in which the shaft isrotatably mounted, a motor having its axis of rotation in alignment withthe shaft for rotating said drum through the medium of said shaft, andmeans external of said bearing supports for moving the shaft and drumlongitudinally as the shaft is rotated.

9. In apparatus of the character set forth, a shaft, a drum fixedlymounted on said shaft, bearing supports in which the shaft is rotatablymounted, means for moving said shaft and drum longitudinally as theshaft is rotated, driving means, and connecting means between saiddriving means and said shaft whereby the shaft is moved relative to saiddriving means while rotated thereby.

10. A device of the character set forth in claim 9, in which theconnecting means comprises an expansion and contraction mechanism havingat least one pair of links, one of said links being pivotally connectedto the shaft and the other pivotally connected to the driving meanswhile both of said links are pivotally connected to each other.

11. In combination: a shaft provided with a drum having a helicalperipheral groove, smooth journals for said shaft, a motor casing androtor for driving said shaft having its axis of rotation in alignmentwith the axis of said shaft, a thrust bearing for preventinglongitudinal movement of said rotor within said motor-casing, meansexternal of said journals for shifting said shaft longitudinally duringthe rotation thereof, a brake adapted to restrain rotation of saidshaft,

and a cable in frictional engagement with a portion of said peripheralgroove.

12. In combination: a sub-base member, a base member movably mounted onsaid sub-base and affording journals for a shaft, a shaft provided witha cable drum journaled in said base member, means for rotatin saidshaft, and means for moving said shaft angitudinally with respect tosaid sub-base in timed relation to the rotation of said shaft.

13. A device as specified in claim 12, in which the base member isanti-frictionally supported on the sub-base by means of a plurality ofroller bearings.

In testimony whereof I afiix my signature.

BERNARD A. SCHROEDER.

